Legem Pone

Money paid down on the nail; ready money. The first of the
psalms appointed to be read on the twenty-fifth morning of the month
is entitled Legem pone, and March 25th is the great pay-day; in
this way the phrase “Legem pone” became associated with cash
down.

“In this there is nothing to be abated; all their speech is legem
pone.” - Minshall: Essayes Prison, p. 26.